The major aim of the proposed research is to obtain a better understanding of the generation of diverse interferons and of their actions. Preliminary evidence suggests that distinct messenger RNAs exist for human leukocyte and fibroblast interferons. We shall attempt to confirm this view and to determine whether distinct mRNA exists for human T (immune) interferon. We also plan to determine whether separate mRNA exists for three different species of mouse interferon. Interferon mRNA will be extracted either from intact cells or from polysomes. Different mRNAs will be injected into Xenopus laevis oocytes and properties of biologically active interferons synthesized in the oocytes will be analyzed. Another approach will be to examine the role of posttranslational modifications in the generation of functionally altered human and mouse interferons.